"Karpo, as always, was dressed in black. His leather coat was black. Even his scarf and fur hat were black. Rostnikov thought that clothes reflected the people who wore them. Rostnikov himself dressed neatly, conservatively, in old comfortable suits and ties Sarah had bought for him at market stalls. As for Karpo's choice of black, Rostnikov was not given to simple judgment. He himself was rather fond of black, which was either the absence of color or the totality of color. There was a statement in black, he thought. Black said, You cannot penetrate my being by looking at my exterior. I am a dark cipher."
— Stuart M. Kaminsky (Murder on the Trans-Siberian Express: A Porfiry Petrovich Rostnikov Novel)